Study And Design On The Information System Of The Fiber-Capacitive Drop Analyzer

The drop analyzer is a new analytical instrument which can analyze the liquid synthetically. The analyzer can measure and discriminate liquids qualitatively and quantitatively by the affections of their physical and chemical parameters. The measurement is operated by monitoring the drop formation process under a certain measuring condition. Comparing with other liquid analysis instruments, the drop analyzer gets more physical and chemical comprehensive parameters directly or indirectly simultaneously. The drop analyzer is the ideal"green instrument"because there isn't any chemical reaction in the testing process,the drop analyzer not only has the strong synthesis testing function, but it is easy for on-line measurement and will be very useful in the liquids measuring fields of environment protection, medicine, drink and so on.Fiber-Capacitive Drop Analyzer is based on merging Fiber drop analysis (FDA) and capacitive drop analysis (CDA), which shows the relation between the light intensity and the instant drop volume, instead of time. It makes the FDT independent from the speed of drop growth and the volatility of liquids, and accordingly ensures the reproducibility of measurement against the variation of the feeding speed of the pump. In addition, the Volume-based Fiber Drop Trace (VFDT) is more favorable for fine discrimination of liquids since it improves the comparability of the VFDT of different liquids.This project aims to make the experimental drop analysis device become a dependable and practical instrumentation. And through some analysis of the experiment results of typical samples, it also provides some practical design schemes for the manufacturing of this device. It is the purpose of this thesis to introduce the systemic project of FCDA and the implementation technology of its components, and to solve and improve the problems in mechanical construction, data acquisition, signal processing and system control.The thesis covers the following aspects concerning the main work:(1) The processing circuits of fiber signal and capacitive signal are introduced in detail. New processing circuits of the Fiber signal and capacitive signal are designed, manufactured and debugged. Moreover, some circuit experiments for system characteristics and stability are carried out.(2)A new set of data acquisition program is designed. (3)Experiments of typical samples are completed, and qualitative comparison and analysis for the experiment results, the"Volume-based Fiber Drop Trace (VFDT)", are presented.